WEDNESDAY, Jan. 1, 2014 (HealthDay News) -- Winter sports and snowy day activities provide lots of exercise and fun, but there's also the risk of injury, an expert warns.

"More than 700,000 injuries are reported each year in the United States due to sledding. More than 30 percent are head injuries, caused by collisions," Dr. Daryl O'Connor, an orthopedic surgeon who specializes in sports medicine at Gottlieb Memorial Hospital, part of the Loyola University Health System, said in a Loyola news release.

He also warned of the potential risks of a number of other sports.

"Lacerations, as well as neck, shoulder and knee injuries are common in hockey. Many injuries are caused through contact with another player, the ice, a puck or [an] actual skate blade," O'Connor said.

As for ice skating, he said that injuries "to the wrist as well as head and neck are most common, and most injuries are caused by falls."

Among snowboarders, wrist and elbow injuries are caused by falling on outstretched hands. And, he warned, skiers knees "really take a pounding and injury is often caused by extreme twisting force propelled by the skis."

O'Connor implored kids and teens to avoid "skitching," which is when someone grabs a car's rear bumper and slides on their feet, or is pulled by ropes on inner tubes or sleds through icy streets.

"This is not even a sport; it's just being foolish," O'Connor said. "In addition to broken bones, neck and shoulder injuries, young people can suffer fatal head trauma. Please, resist the skitch at all costs."